class iter2(object):
'''Takes in an object that is iterable. Allows for the following method
calls (that should be built into iterators anyway...)
calls:
- append - appends another iterable onto the iterator.
- insert - only accepts inserting at the 0 place, inserts an iterable
before other iterables.
- adding. an iter2 object can be added to another object that is
iterable. i.e. iter2 + iter (not iter + iter2). It's best to make
all objects iter2 objects to avoid syntax errors. :D
'''
def __init__(self, iterable):
self._iter = iter(iterable)
def append(self, iterable):
self._iter = itertools.chain(self._iter, iter(iterable))
def insert(self, place, iterable):
if place != 0:
raise ValueError('Can only insert at index of 0')
self._iter = itertools.chain(iter(iterable), self._iter)
def __add__(self, iterable):
return itertools.chain(self._iter, iter(iterable))
def next(self):
return self._iter.next()
def __iter__(self):
return self
def flatten(iterable):
'''flatten a list of any depth'''
iterable = iter2(iterable)
for e in iterable:
if hasattr(e, '__iter__'):
iterable.insert(0, e)
else:
yield e
Diff to Previous Revision
--- revision 5 2012-04-03 16:49:02
+++ revision 6 2012-04-03 17:13:35
@@ -13,15 +13,15 @@
self._iter = iter(iterable)
def append(self, iterable):
- self._iter = itertools.chain(self._iter, iterable)
+ self._iter = itertools.chain(self._iter, iter(iterable))
def insert(self, place, iterable):
if place != 0:
raise ValueError('Can only insert at index of 0')
- self._iter = itertools.chain(iterable, self._iter)
+ self._iter = itertools.chain(iter(iterable), self._iter)
def __add__(self, iterable):
- return itertools.chain(self._iter, iterable)
+ return itertools.chain(self._iter, iter(iterable))
def next(self):
return self._iter.next()
@@ -31,15 +31,9 @@
def flatten(iterable):
'''flatten a list of any depth'''
- # note for newbies: pulling off the member function (as the next line does)
- # is a way to speed up (not by much haha)
- # potentiolly long running functions. It is equivalent
- # to: iterable = iter2(iterable)
- # and then calling: iterable.insert(0, e)
- # variables in python's local scope are accesssed much faster.
- insert_iter = iter2(iterable).insert
+ iterable = iter2(iterable)
for e in iterable:
if hasattr(e, '__iter__'):
- insert_iter(0, e)
+ iterable.insert(0, e)
else:
yield e
